Head-of-rail bond



Dec. 23, 1952 r F. c. LAVARACK HEAD-OF-RAIL. BOND Filed Sept. 9, 1949 INVENTOR.

9M1 MTTORNEY Patented Dec. 23, 1952 UNITED STAT FFICE Application September El, 1949, Serial No. 114,800

2 Claims. 1

This invention relates to electrical conductors particularly electrical conductors known as rail bonds, and especially to the form of rail bonds known as head-of-rail bonds.

A principal object of this invention is to construct a bond of the type specified which will be extremely inexpensive to construct, extremely easy to install, formed of a minimum of material, exhibiting a minimum of obstruction to dragging railway equipment parts and which may be most securely mechanically and elec trically attached in a cavity in the side of a rail head by the use of a hammer and punch.

Other objects and advantages will appear the description of the particular physical embodiment selected to illustrate the invention progresses and the novel features will be particularly pointed out in the appended claims.

In describing the invention in detail and the particular physical embodiment selected to illustrate the invention, reference will be had to the accompanying drawings and the several views thereon, in which like characters of reference designate like parts throughout the several views, and in which:

Figure 1 is a fragmentary side elevational view of two abutting rails with a rail bond of my construction installed in place thereon; Fig. 2 is a fragmentary cross sectional view of the device as shown by Fig. l on the plane indicated by the line 11-11 viewed in the direction of the arrows; Fig. 3 is a fragmentary view similar to Fig. 2 but on an enlarged scale in order to more clearly show the construction; Fig. 4 is a fragmentary view of a portion of a cable and the metal plug attached to the end thereof used in my invention; Fig. 5 is a cross sectional view of the device as shown by Fig. 4 on the plane indicated by the line V-V viewed in the direction of the arrows at the ends of the line; Fig. 6 is a cross sectional view similar to Fig. 3 but illustrating a portion of a punch or driver used in the operation of affixing my bond to a rail head; Fig. '7 is a cross sectional view of the device as shown by Fig. 6 on the plane indicated by the line VIIVII viewed in the direction of the arrows at the ends of the line and indicating the position of a punch used in the operation of attaching my bond to a rail bond; Fig. 8 is a side el vational view, with a portion broken away, to more clearly show the construction of a punch used in connection with my invention; Fig. 9 is a cross sectional view on the plane indicated by the line 1XIX of Fig. 8 viewed in the direction of the arrows at the ends of the line.

Those skilled in the art of railway signalling are Well aware that a most vulnerable part of a railway track circuit is the bond connecting the abutting ends oi adjacent rails because it is exposed to all kinds of weather and is positioned so that it is likely to be struck and damaged by dragging railway equipment. It is also well known that these bonds are positioned on the de of the track rail, in most cases each 39 cng the trackway, so that a considerable e caused by the mere purchase thereof l a still greater expense to properly install y invention provides a bond of the head-ofrail type which requires, relative to present day bonds, a minimum of material, and it is, therefore, possible to sell them at a minimum price. My bond also is so constructed that it may be applied to a rail head by a relatively unskilled person so as to make the most intimate mecham ical and electrical contact with the metal of a rail. My bond is also so constructed that the terminal plugs thereof are most intimately and satisfactorily, mechanically and electrically connected to the usual cable and the afiixing of the plugs of the bonds into the rail heads assists, rather than detracts, from the intimate mechanical and electrical contact between the cable and the plug.

in order to secure the above mentioned advantages, and others, 1 construct and apply my bonds as illustrated in the accompanying drawings and as hereinafter described.

Fig. 1 illustrates the end of two abutting rails of a railway track and have been designated 1 and My bond designated as a whole by B includes an electrically conducting metallic cable 3 and two plugs i and 5, each plug seated in a cavity opening in the side face of a rail head.

The conductor 3 may be of any appropriate or usually used metal and may be solid or stranded. I prefer a standard cable 3.

The plugs, as 5, of my invention are of metal. I prefer malleable copper. They are generally of a cylindrical form with a fiat outer face and a fiat or coned inner face as preferred. I prefer the coned inner face as shown at 8. These solid plugs 5 are formed by the usual or ordinary mechanical method as by drilling to form cavity i. This cavity i has its longitudinal axis preferacly displaced from the central longitudinal axis to the plug 53 as well shown in Figs. 3 and 4, but I do not mean to exclude a construction in which the cavity is central of plug 5.

After the cavity 7 is formed in a plug 5, one

end of an electrical conductor, as the cable 3, of a plurality of strands, is inserted in the cavity as far as it will go and then the entire periphery as 8 and 9 is compressed or swaged so that the material of plug 5 and the material of cable 3 are intimately brought together or driven together and the strands of the cable somewhat distorted, so that all interstices are obliterated, with the material of the plug protruding therein, and the material of plug 5 and the material of the conductor 3 are in effect one, both mechanically and electrically or at any rate, they are so in timately squeezed one into the other that there is no opportunity for air or moisture to enter or get between the various parts so as tostart corrosion and injury or deteriorate the mechanical and electrical union. This swaging is so done that the external diameter of the plug is such that it will just fit into the standard %-inch diameter cavity In in the rail head, that is to a predetermined size. The plug 5 after the swaging is preferably of a length such that the outer face II thereof will be within the line of the outer face l2 of the side of the rail head when the plug 5 is inserted and gently tapped into place.

After the plug 5 is put into place, as shown by Fig. 6, the outside face should be at about the line l3 as shown in Fig. 6. In order to permanently aflix the plug 5 in the cavity if! a punch I i, driven by a hand hammer, is then used to drive the plug 5 firmly home and expand it within the cavity m.

The punch B has the usual handle portion NE, of polygonal cross section, and a particularly constructed driving end IS. The extreme end H3 of the punch is a plane at a right angle to the longitudinal axis of the punch M, preferably, but I do not exclude an inclined or other formed face. Adjacent the end, the punch is reduced in external diameter and has a partial arcuate periphery I1 terminating in a plane parallel to the longitudinal axis of the punch, that is, the plane through the points l8 and 19 of Fig. 9. The punch is further formed adjacent the end with an arcuate cavity 28 parallel to the longitudinal axis of the punch and opening at the end face and in the plane parallel to the longitudinal axis. The outer periphery of the end I6 just fits within the cavity 1 and substantialy coincides with the inner surface of cavity in adjacent thereto for the greater portion of the end of the punch, that is, from point l8 around the curve to point It. The cable 3 is received within the cavity 20 and the surface of this cavity 26 substantially fits a portion of the periphery of the cable 3 to which it is adjacent. The net result is, as best shown perhaps in Fig. 7 in dotted lines.

Upon driving punch l 4 with a suitable tool, as a hand hammer, the plug is compressed longitudinally and expanded sidewise so that it tightly contacts the inside surface of the cavity i9, thus making a very tight and perfect mechanical and electrical contact.

The driving of plug 5 by the punch 4 tends to further compress the material of the plug around the cable 3 and also force the strands of the cable closer together, so that the driving assists the former swaging.

It should also be noted that the ends of the punch I 4 almost completely covers the head or outer face of the plug 5, that is the major portion thereof, so that the driving is most effective to bind the plug in the cavity 16, because practically all of the metal of the plug is con- 4 fined between the punch and the walls of the cavity.

The driving will result in the face of the plug being forced inwardly from about line i3 of Fig. 3 to line I l, and during the driving the punch will be practically guided by reason of its relation to the curved surface of the cavity.

From the hereinbefore given description it will also be seen that my improved bond terminal and bond is so constructed and so applied that an extremely good electrical and mechanical contact is obtained between the surface of the plug and the curved surface of the cavity It. It is furtherto be observed that my construction, as the final heavy blows to finally affix the plug in the cavity [0, are applied to the plug when it is all or substantially all within the cavity I0, that there is no opportunity to drive the plug into the cavity) at an angle to the longitudinal axis of the cavity 10, so that one side of the plug might bear upon the edge of the cavity and have that edge out into the body of the plug while leaving the other side of the plug separated from the inside surface of the cavity.

It should further be noted that, unlike other head-of-rail bonds of the prior art, my bond has only a quite flexible stranded metallic cable outside of the cavities in the rail head. Such a body can give and not break when struck by dragging railway rolling stock equipment, whereas bonds of the prior art, having a solid portion of the bond protruding from the rail head cavity are more likely to be broken or cut off under such conditions.

A further most important feature of my bond is that it is practically immaterial to the proper affixing of my plug in the rail head cavity that the cavity is made deeper than standard. If the cavity is deeper than standard, the plug merely sinks deeper into the rail head, and when it has contacted the end wall of the cavity, the driving force applied to its outside face expands it just as properly as though the cavity were the standard depth. The absence of any enlargement upon my plug 5 that is intended to rest against the outside face of the rail head is also a decided advantage because there is nothing to be distortedor damaged when'an attempt is made to affix the plug in a hole which is deeper than standard.

Above all, as the plug is entirely within the cavity in the rail when being expanded, every bit of distortion or expansion aids in completely filling the cavity in the rail head and holding the plug in place therein. This is unlike that form of bond in which there is'a protuberance extending outwardly beyond the side face of the rail and which may be hammered quite forcibly without any substantial expansion or distortion taking place in th material within the cavity in the rail head.

It is further to be noted that my bond, unlike some other bondsof the prior art, is constructed of three parts only, and these three parts are so firmly and permanently united that there is absolutely no'danger of any one part becoming separated from the others. Further, the Signalman, applying the bonds, has no assembly to perform before applying the bond.

Although I have particularly described one particular physical embodiment of invention and explained the construction and principle thereof, nevertheless, I desire to have it understood that the'form selected is merely illustrative, but does not exhaust thepossible physical embodiments of the idea of means underlying my invention.

What I claim as new and desire to secure by Letters Patent is:

1. The method of afiixing an electrical conductor in a cavity in a rail which comprises first forming a plug of malleable metal with a longitudinal cavity therein opening in an end face only with its longitudinal axis displaced from the longitudinal axis of the plug, then inserting an end of a metallic electrical conductor in the cavity in the plug, then swaging the plug to drive themtal 01 the plug and of the conductor into intimate mechanical and electrical contact, then placing the plug with the conductor attached thereto in a cavity in a rail and then driving the plug by pressure against the major portion of the face thereof applying the final blow to firmly aflix the plug in the cavity while the outer face of the plug is inwardly of the plane of the opening 01 the cavity. f

2. A rail bond, including, in combination, a cable of electrically conducting metal, a plug of malleable metal formed with a longitudinal cavity FREDERICK c. LAVARACK.

REFERENCES CITED The following references are of record in the file 01 this patent:

UNITED STATES PATENTS Number Name Date 470,820 Garland Mar. 15, 1882 1,585,327 Booker May 18, 1926 2,180,318 Deems Nov. 14, 1939 2,197,793 Everett Apr. 23, 1940 2,311,874 Sabol Feb. 23, 1943 2,498,114 Penrod Feb. 21, 1950 

